1. Field of the Invention
This invention relates to optical disk systems, and in particular to optical disk systems which allow users to choose among a variety of playback viewing and listening options.
2. Description of the Related Art
Optical disks are recording media typically containing long strings of microscopic pits representing digitally encoded data. Each string of pits is called a xe2x80x9ctrackxe2x80x9d. The tracks are formed end to end in a spiral pattern around the center of one or both major surfaces of the disk. Reflected laser light is used to xe2x80x9creadxe2x80x9d the data encoded in the pits. Common types of optical disks available today include compact disks (CDs), laser video disks, and digital versatile disks (DVDs). Various optical disk players are available which read data from optical disks.
The current DVD standard is a compromise format agreed upon by several major consumer electronic and entertainment companies. Under the current DVD standard, the capacity of a single side, single layer DVD with a diameter of 4.7 inches is 4.7 gigabytes, enough to store about 135 minutes of video data. This capacity is sufficient for about 95% of all full length movies. The current DVD standard also provides for up to eight different sound tracks in different languages, each with up to eight different audio channels to create a three-dimensional acoustic effect. In addition, up to 32 different sets of subtitles (i.e., translation text) may be stored on a DVD for display during playback.
By virtue of the numerous capabilities afforded by the DVD standard, a typical DVD player allows a user to select among a wide variety of viewing and listening options. The user typically makes these selections by navigating through several layers of menus displayed upon a television (TV) screen. For example, viewing options include display format, camera angle, and subtitles. A standard TV has a width-to-height (i.e., aspect) ratio of 4:3, while a widescreen TV has an aspect ratio of 16:9. Video data can be stored on a DVD for standard TV (4:3 display data) or widescreen TV (16:9 display data). DVD player display format options include full frame (4:3 format from 4:3 display data), letterbox (4:3 format from 16:9 display data), pan and scan (4:3 format from 16:9 display data), and widescreen (16:9 format from 16:9 display data). In letterbox format, a wide black stripe is added across the tops and bottoms of the 16:9 display data images such that proper proportions are maintained when the images are displayed upon a 4:3 screen. In pan and scan format, only 4:3 portions of the 16:9 display data images are displayed. Images xe2x80x9cshotxe2x80x9d from several different camera angles may be recorded on the disk, and the user may select any one of these camera angles for viewing. Subtitles in any one of up to 32 different languages may be superimposed upon portions of the images.
Audio options include language, number of channels, dynamic range, and volume. The user may select one of up to 8 different languages for playback. The user may also select desired values for number of audio channels, dynamic range, and volume. As described above, each of the up to 8 sound tracks in different languages may have up to 8 audio channels. Audio data encoded using Dolby(copyright) AC-3(trademark) may have 1 to 5.1 channels. Audio data encoded using MPEG-2 audio may have 1 to 5.1 or 7.1 channels. Audio data encoded using pulse code modulation (PCM) may have 1 to 8 channels. A user may select from the various audio options present on a disk.
Users may have different viewing and listening preferences. Each user""s preferences, however, would not be expected to change significantly over time. As a result, a typical user will most likely grow tired of having to reselect the same viewing and listening preferences each time a presentation (e.g., a movie) is viewed. It would thus be beneficial to have an optical disk system which stores information specific to each optical disk and/or user. Such a system would conveniently allow a user to view a presentation, or to continue viewing an interrupted presentation, without having to reselect viewing and listening preferences.
The problems outlined above are in large part solved by an optical disk system and method for storing disk- and user-specific settings. One embodiment of the optical disk system includes a disk drive unit for retrieving identification data and encoded video data stored upon an optical disk, an input device for inputting user settings, and a microprocessor memory unit operably coupled to the disk drive unit and the input device and including a non-volatile portion for storing the identification data and the user settings. Information specific to optical disks (e.g., DVDs) and users is stored within the non-volatile portion of the microprocessor memory unit. Such information may be retrieved and invoked, conveniently allowing a user to view a presentation, or to continue viewing an interrupted presentation, without having to reselect viewing and listening preferences.
The identification data may include a portion of a title of the optical disk. A value corresponding to the identification data may be stored within the non-volatile portion of the microprocessor memory unit in order to minimize storage requirements. The value may be, for example, an error detection code (e.g., checksum) computed from the identification data stored upon the optical disk.
The non-volatile portion of the microprocessor memory unit may include, for example, flash memory or electrically erasable programmable random access memory (EEPROM) which maintains stored contents even in the absence of applied electrical power.
The input device may include a keypad having multiple electrical pushbutton switches or xe2x80x9ckeysxe2x80x9d. The input device may be a xe2x80x9cremotexe2x80x9d control unit in wireless communication with the microprocessor (e.g., via an infrared light beam). A user may input user settings by pressing one or more of the keys of the keypad. The user settings may include, for example, spoken language, video display format, audio volume setting, and subtitle language.
The optical disk system may also include a microprocessor and an audio/video decoder. The microprocessor may be coupled to the disk drive unit and the microprocessor memory unit, and may be operably coupled to the input device. The microprocessor may receive the identification data from the disk drive unit and the user settings. The user settings may be retrieved from the non-volatile portion of the microprocessor memory unit. Alternately, the user input may be received via the input device.
The microprocessor may be configured to: (i) store the identification data and the user settings within the non-volatile portion of the microprocessor memory unit, and (ii) provide the identification data and the user settings. The audio/video decoder may be coupled to the disk drive unit and the microprocessor. The audio/video decoder may receive the encoded video data from the disk drive unit and the identification data and user settings from the microprocessor. The audio/video decoder may decode the encoded video data thereby producing decoded video data, and may produce image data (e.g., bit-mapped textual data) which reflects the identification data and the user settings. The audio/video decoder may produce a video output signal which includes the image data superimposed upon the decoded video data.
The microprocessor may maintain a table including disk identification data and disk specific settings (e.g., user settings and last stop playback location information) within the non-volatile portion of the microprocessor memory unit. The table may have multiple entry locations, wherein each entry location corresponds to a specific disk and has a disk identification field and a specific settings field. The specific settings field may be used to store the user settings and last stop playback information associated with the disk identified by the data within the disk identification field.
The microprocessor may also maintain a table including user specific settings within the non-volatile portion of the microprocessor memory unit. The table may have multiple entry locations, wherein each entry location corresponds to a specific user and has a user identification field and a specific settings field. The specific settings field may be used to store the user settings associated with the user identified by the data within the user identification field.
When an optical disk is inserted into the disk drive unit, the microprocessor receives the disk identification data (e.g., textual title) from the disk drive unit. The microprocessor may search the table for an entry with matching identification data in the identification field. If an entry with matching identification data is not found, the user may be given the option of using settings stored within the table of user specific settings. If the table of user specific information is empty, or the user chooses not to use settings stored within the table of user specific settings, the microprocessor may prompt the user to enter viewing and listening preferences via the input device. If the user settings are entered via the input device, the settings may be stored within the table of user specific information. After the user settings are obtained, the microprocessor may initialize the last stop playback location to a beginning location. The microprocessor may select an entry location for the disk within the table of disk specific information, and store the identification data, the current calendar date, the last stop playback location, and the user settings within the entry location.
If an entry location with matching disk identification data is found, the microprocessor may retrieve the calendar date, the last stop playback location, and the user settings from the specific settings field of the entry location. The microprocessor may then provide the identification data, the calendar date, the last stop playback location, and the user settings to an on-screen display unit of the audio/video decoder. The on-screen display unit may produce the image data reflecting the disk identification data the calendar date, the last stop playback location, and the user settings. The identification data, the calendar date, the last stop playback location, and the user settings may then be displayed upon the display screen of the display device, and the user may be given the option of resuming playback from the last stop playback location and with the previously selected user settings. Resuming playback from the last stop playback location keeps the user from having to xe2x80x9chuntxe2x80x9d through the presentation to determine a suitable location to resume playback. Allowing the user to resume playback with the previously selected user settings saves the user the time and trouble of reselecting viewing and listening preferences.
The present method for controlling the operation of the optical disk system includes obtaining identification data from the optical disk when the optical disk is inserted into the disk drive unit, obtaining user settings, and storing the identification data and the user settings within the non-volatile portion of the microprocessor memory unit. The disk drive unit may be used to scan the optical disk to obtain the identification data. The microprocessor may receive the identification data, and may search the table of disk specific information in order to determining if the optical disk has been inserted into the disk drive unit before. If the optical disk has been inserted into the disk drive unit before, the last stop playback location and the user settings may be retrieved and invoked. If the optical disk has not been inserted into the disk drive unit before, the user settings associated with the optical disk may be obtained from the table of user specific settings. Alternately, the user settings may be obtained via the input device. If the user settings are obtained using the input device, the user settings may be stored within the table of user specific settings. Once the user settings are obtained, retrieval of presentation data (i.e., encoded audio and video data) from the optical disk may be initiated.
If playback of the presentation data is stopped before an end of the encoded video and audio data on the optical disk is reached, the optical disk system may store the identification data, the user settings, and last stop playback location within the non-volatile portion of the microprocessor memory unit. The next time the optical disk is inserted into the disk drive unit, the information data, the user settings, and the last stop playback location may be displayed, and the user may be asked if playback should be restarted from the last stop point and with the previous audio and video settings.
A sleep timer function may also be employed to detect when a user falls asleep during playback. During playback, a visual signal (e.g., an icon) may be periodically displayed (e.g., every 30 minutes) within a portion of the display screen of the display device. The user may be required to respond to the visual signal (e.g., by pressing one or more keys of the keypad of the input device) within a predetermined amount of time (e.g., 5 minutes) in order for playback to continue. The visual signal may be displayed in, for example, a corner of the display screen. The time interval between displays of the visual signal may be determined by a first timer. Display of the visual signal may start a second timer which determines the required response time.
When a sleep timer mode is activated, the first and second timers may be enabled. The first timer may be activated when playback is initiated. When the first timer indicates a first predetermined period of time has elapsed (e.g., 30 minutes), the visual signal may be displayed and the second timer activated. The microprocessor may initiate display of the visual signal by providing data pertaining to the visual signal to the on-screen display unit. The on-screen display unit may produce image data and store the image data within an audio/video memory unit. The audio/video decoder may retrieve the image data from the audio/video memory unit, incorporate the image data into the output signal, and provide the output signal to the display device via a video signal encoder.
Each time the user responds to the visual signal via the input device within the predetermined time period of the second timer (e.g., 5 minutes), the microprocessor may store the identification data, the user settings, and the current playback location as the last stop playback location within the non-volatile portion of the microprocessor memory unit. The microprocessor may direct the on-screen display unit to stop producing image data. The visual signal disappears from the display screen of the display device, and playback continues.
If the user fails to respond to the visual signal via the input device within the predetermined time period of the second timer, the optical disk system assumes the user is asleep. The microprocessor stops playback and interrupts the supply of electrical power to the other components (i.e., shuts down the optical disk system). The non-volatile portion of the microprocessor memory unit holds the disk identification data, the user settings, and the last stop playback location stored the last time the user responded to the visual signal. The next time the disk is inserted into the disk drive unit, the user will be asked if playback should be continued from the location corresponding to the last time the user responded to the visual signal (i.e., just before the user fell asleep).